package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.hmdp.utils.UserHolder;
import lombok.RequiredArgsConstructor;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    private final StringRedisTemplate stringRedisTemplate;
    private final UserServiceImpl userService;
    public FollowServiceImpl(StringRedisTemplate stringRedisTemplate,UserServiceImpl userService) {
        this.stringRedisTemplate = stringRedisTemplate;
        this.userService=userService;
    }

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        Long userId = UserHolder.getUser().getId();
        String key="follows:"+userId;
        //判断关注还是取关
        if (isFollow) {
            //关注新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if (isSuccess) {
                //关注用户的id放入redis的set集合 sadd userid followuserid
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
            //取关，删除 delete from tb_follow where userId=? and follow_user_id=?
            boolean isSuccess=remove(new QueryWrapper<Follow>().eq("user_id",userId).eq("follow_user_id",followUserId));
            if (isSuccess) {
                stringRedisTemplate.opsForSet().remove(key,followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        //查询是否关注 select from tb_follow where userId=? and follow_user_id=?
        Integer count = query().eq("user_id", userId).eq("follow_user_id", followUserId).count();
        return Result.ok(count>0);
    }

    @Override
    public Result followCommons(Long id) {
        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key="follows:"+userId;
        //求交集
        String key2="follows:"+id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if (intersect==null||intersect.isEmpty()){
            //无交集
            return Result.ok(Collections.EMPTY_LIST);
        }
        //解析id集合
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> users = userService.listByIds(ids).stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(users);
    }
}
